General Pathology Practice Questions

Q: In apoptosis, permeabilization of which membrane occurs?

Mitochondrial membrane. ### Explanation **Correct Option: D. Mitochondrial Membrane** Apoptosis (programmed cell death) is primarily regulated through the **intrinsic (mitochondrial) pathway**. The central event in this pathway is the **Mitochondrial Outer Membrane Permeabilization (MOMP)**. This process is controlled by the Bcl-2 family of proteins. Pro-apoptotic proteins like **BAX and BAK** create pores in the outer mitochondrial membrane, leading to the leakage of **Cytochrome c** into the cytosol. Once in the cytosol, Cytochrome c binds with APAF-1 to form the **apoptosome**, which activates Caspase-9, eventually leading to cell death. **Why other options are incorrect:** * **A. Nuclear membrane:** While nuclear changes like chromatin condensation (pyknosis) and fragmentation (karyorrhexis) occur during apoptosis, the permeabilization of the nuclear membrane is not the initiating or defining event. * **B. Cytoplasmic membrane:** In apoptosis, the plasma membrane remains **intact** (though it undergoes "blebbing") to prevent the leakage of cellular contents and subsequent inflammation. This is a key distinction from **necrosis**, where the plasma membrane is ruptured. * **C. Lysosome:** Lysosomal membrane rupture is typically associated with autolysis or necrotic cell death. In apoptosis, organelles are generally sequestered into apoptotic bodies rather than being lysed. **High-Yield Clinical Pearls for NEET-PG:** * **Anti-apoptotic proteins:** Bcl-2, Bcl-xL (they maintain membrane stability). * **Pro-apoptotic proteins:** BAX, BAK (the "executioners" that cause permeabilization). * **BH3-only proteins:** BIM, BID, BAD (the "sensors" that initiate the pathway). * **Morphological Hallmark:** Apoptosis is characterized by cell shrinkage and intact membranes, whereas necrosis involves cell swelling and membrane rupture. * **Biochemical Hallmark:** DNA laddering (due to internucleosomal cleavage by endonucleases).

Q: Heart failure cells are seen in which condition?

Chronic venous congestion of the lung. **Explanation:** **Heart failure cells** are **hemosiderin-laden macrophages** found in the alveoli. They are the hallmark of **Chronic Venous Congestion (CVC) of the lung**, typically resulting from left-sided heart failure. [1] **Why Option B is correct:** In left-sided heart failure, the heart cannot pump blood efficiently, leading to increased pressure in the pulmonary veins. This causes congestion of the pulmonary capillaries. [1] The high pressure forces red blood cells (RBCs) to extravasate into the alveolar spaces. Alveolar macrophages then phagocytose these RBCs and break down the hemoglobin into **hemosiderin**, a golden-brown pigment. The presence of these pigmented macrophages in the lung tissue or sputum indicates chronic congestion. **Why other options are incorrect:** * **Options A & D (Liver):** CVC of the liver presents with a "Nutmeg liver" appearance due to congestion around the central veins. While it involves macrophages (Kupffer cells), the specific term "heart failure cells" is reserved for pulmonary pathology. * **Option C (Acute Lung Congestion):** In acute stages, there is edema and hemorrhage, but there has not been enough time for macrophages to ingest RBCs and convert them into visible hemosiderin. **High-Yield NEET-PG Pearls:** * **Nutmeg Liver:** Characteristic of CVC of the liver (central hemorrhagic necrosis vs. fatty peripheral zones). * **Brown Induration:** The gross appearance of the lungs in long-standing CVC due to the combination of hemosiderin deposition and fibrosis. * **Prussian Blue Stain:** Used to confirm the presence of iron (hemosiderin) within heart failure cells, staining them deep blue.

Q: Red infarcts occur in which of the following organs?

Lung. ### Explanation Infarction occurs due to tissue necrosis resulting from ischemia. Infarcts are classified into two types based on their color and the nature of the blood supply: **Red (Hemorrhagic)** and **White (Anemic)**. **Why the Lung is Correct:** Red infarcts occur in tissues with a **dual blood supply** or loose stroma that allows blood to collect in the necrotic area. The lung receives blood from both the **pulmonary arteries** and **bronchial arteries**. When a pulmonary artery branch is obstructed, the bronchial circulation continues to pump blood into the necrotic zone, but the damaged tissue cannot contain it, leading to hemorrhage. Other sites for red infarcts include the small intestine (dual supply/collaterals), brain (liquefactive necrosis), and tissues following venous torsion (e.g., testis or ovary). **Why Other Options are Incorrect:** * **A, C, and D (Kidney, Spleen, Heart):** These are solid organs with **end-arterial circulation** (single blood supply). When the primary artery is blocked, there is no secondary source of blood to fill the area. This results in a **White (Anemic) Infarct**, which appears pale and wedge-shaped. **High-Yield NEET-PG Pearls:** * **White Infarcts:** Occur in solid organs with end-arteries (Heart, Spleen, Kidney). * **Red Infarcts:** Occur in organs with dual blood supply (Lung, Liver, GI tract), loose tissues, or following venous occlusion. * **Morphology:** Most infarcts are wedge-shaped, with the apex pointing toward the site of vascular occlusion. * **Reperfusion Injury:** Red infarcts can also occur when blood flow is restored to a previously ischemic/necrotic area.

Question 1

Which of the following is false regarding reversible cell injury?

Accepted Answer

Breakdown of plasma membrane

Answer

Detachment of ribosomes from the endoplasmic reticulum (ER)

Answer

Hydropic change

Answer

Accumulation of myelin figures in the cytoplasm

Question 2

Which of the following is a congenital deformity?

Accepted Answer

Congenital talipes equinovarus (CTEV)

Answer

Potter sequence

Answer

Congenital heart disease

Answer

Cleft lip

Question 3

In apoptosis, permeabilization of which membrane occurs?

Accepted Answer

Mitochondrial membrane

Answer

Nuclear membrane

Answer

Cytoplasmic membrane

Answer

Lysosome

Question 4

Heart failure cells are seen in which condition?

Accepted Answer

Chronic venous congestion of the lung

Answer

Chronic venous congestion of the liver

Answer

Acute venous congestion of the lung

Answer

Acute venous congestion of the liver

Question 5

Increased functional demand on the heart produces an increased size of the myocardium by which of the following mechanisms?

Accepted Answer

Hypertrophy

Answer

Hyperplasia

Answer

Calcification

Answer

Fatty infiltration

Question 6

Red infarcts occur in which of the following organs?

Accepted Answer

Lung

Answer

Kidney

Answer

Spleen

Answer

Heart

Question 7

All of the following is an example of squamous metaplasia except:

Accepted Answer

Esophagus in gastric reflux

Answer

Cervix in case of chronic irritation

Answer

Respiratory tract in case of smoking

Answer

Stone in bile ducts

Question 8

Necrosis with putrefaction is called as:

Accepted Answer

Gangrene

Answer

Desiccation

Answer

Liquefaction

Answer

Coagulative necrosis

Question 9

A study of aging shows that senescent cells have accumulated damage from toxic byproducts of metabolism, with increased intracellular lipofuscin deposition. Prolonged ingestion of which of the following substances is most likely to counteract this aging mechanism?

Accepted Answer

Antioxidants

Answer

Analgesics

Answer

Antimicrobials

Answer

Antineoplastic agents

Question 10

On electron microscopy, amyloid characteristically exhibits which of the following?

Accepted Answer

7.5-10 nm fibrils

Answer

Beta-pleated sheets

Answer

Hyaline globules

Answer

20-25 nm fibrils

General Pathology — MCQs

General Pathology — MCQs

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